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Search: id:A068084
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| A068084 |
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Smallest triangular number which is a multiple (>1) of the n-th triangular number. |
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+0
1
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| 3, 6, 36, 120, 45, 105, 1176, 2016, 630, 990, 528, 780, 3003, 210, 3240, 32640, 9180, 11628, 2850, 630, 3003, 26565, 16836, 20100, 44850, 52650, 17766, 20706, 10440, 12090, 461280, 61776, 11781, 3570, 25200, 43956, 221445, 30381, 5460, 189420
(list; graph; listen)
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OFFSET
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1,1
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EXAMPLE
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The fifth triangular number is 15; the next triangular number that's divisible by 15 is 45, so a(5)=45.
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MATHEMATICA
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a[n_] := For[k=n+1, True, k++, If[Mod[k(k+1), n(n+1)]==0, Return[k(k+1)/2]]]
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CROSSREFS
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Sequence in context: A119184 A084260 A076983 this_sequence A003674 A120595 A048642
Adjacent sequences: A068081 A068082 A068083 this_sequence A068085 A068086 A068087
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KEYWORD
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easy,nonn
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AUTHOR
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Amarnath Murthy (amarnath_murthy(AT)yahoo.com), Feb 18 2002
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EXTENSIONS
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Edited by Dean Hickerson (dean(AT)math.ucdavis.edu), Feb 20 2002
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